1. Field of the Invention
This invention concerns settling tanks in general. More specifically it concerns an improved settling tank structure, for use in oil and water mixtures.
2. Description of the Prior Art
Heretofor, settling tanks for separating oil from water, particularly where there has been some emulsion formed, have merely involved a rather large sized tank for making a separation by settling therein. A standard 1000 barrel settling tank has a dimension of approximately 16 feet high and is about 21 feet 7 inches in diameter. The inlet for introducing a mixture of liquids, is located on one side near the top. An outlet for the settled liquid (which is suppose to be all water) is located on the other side of the tank near the bottom. Also there is a water leg, or inverted U-tube connected to the outlet and extending up near the top of the tank. This is for maintaining a static fluid level in the tank. There is usually an outlet for the settled-out oil near the top and above the inlet on the same side as the inlet. If the tank is covered, there is, of course, an outlet for gas.
It has been found that separation in such a settling tank is not very efficient, and much emulsion with oil in the mixture is retained and flows out the outlet.
There is a prior U.S. Pat. No. 1,217,397 issued Feb. 27, 1917, which deals with filtering of water containing precious metals in order to recover such precious metals. It discloses a tank with partitions, and the water containing the metals is circulated therethrough. But, the water is kept moving at a sufficient rate to retain the metal particles in the fluid stream all the way through the tank and out the exit end thereof.
There is also a prior U.S. Pat. No. 2,288,333 to D. W. Vinson issued June 30, 1942. However, it discloses a special type of settling tank which while it has partitions, includes an open space along the bottoms of such partitions. Also, the alternate partitions are attached to one of the walls so that the field circulates through in an S-shaped stream above the bottom open portions.
It is an object of this invention to provide a settling tank structure that is improved over the prior known structures. The improvement is such as to create a substantially complete separation during the settling process, as fluid is translated through the settling tank.